//https://leetcode.cn/problems/single-number/
int singleNumber(int* nums, int numsSize) {
    int tmp = 0;
    int j = 0;
    for (int i = 0; i < numsSize; ++i)
    {
        int flag = 1;
        j = 0;
        while (j < numsSize)
        {
            if (j != i && nums[i] == nums[j])
            {
                flag = 0;
                break;
            }
            ++j;
        }
        if (flag)
        {
            tmp = nums[i];
            break;
        }
    }
    return tmp;
}